Communication system, mobility management network element and method for processing resource

ABSTRACT

A method for processing resource, a communication system, and a mobility management network element are provided. The method includes: receiving, by a mobility management network element in a packet switched (PS) network, a Release Request message sent by an access network of the PS network or a Handoff Complete message sent by a circuit switched (CS) network when a user equipment (UE) is handed over from the PS network to the CS network; and processing, by the mobility management network element of the PS network, resources of the UE in the PS network. Thus, the processing of resources of the UE in the PS network is achieved when the UE is handed over from the PS network to the CS network. A communication system and a mobility management network element are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No.200810067044.0, filed Apr. 30, 2008, Chinese Patent Application No.200810188447.0, filed on Dec. 17, 2008, and International PatentApplication No. PCT/CN2009/070787, filed on Mar. 13, 2009, all of whichare hereby incorporated by reference in their entirety.This applicationis a reissue continuation of U.S. patent application Ser. No.14/464,493, filed on Aug. 20, 2014, now U.S. Pat. No. RE 46,440 which isa reissue continuation of U.S. patent application Ser. No. 13/623,879,filed on Sep. 21, 2012, now U.S. Pat. No. RE 45,133, which is a reissueapplication of U.S. patent application Ser. No. 12/430,409, filed onApr. 27, 2009, now U.S. Pat. No. 7,801,803. The U.S. patent applicationSer. No. 12/430,409 claims priority to an International Application No.PCT/CN2009/070787, filed on Mar. 13, 2009, and Chinese PatentApplication No. 200810067044.0, filed on Apr. 30, 2008 and a ChinesePatent Application No. 200810188447.0, filed on Dec. 17, 2008. Theafore-mentioned patent applications are hereby incorporated by referencein their entireties.

TECHNICAL FIELD

The present invention relates to the field of communication technology,and more particularly to a method for processing resources, acommunication system, and a mobility management network element.

BACKGROUND

FIG. 1 shows a conventional interworking architecture of a 3^(rd)Generation Partnership Project (3GPP) packet switched (PS) network and aCDMA2000 1x network in a code division multiple access (CDMA) network.Referring to FIG. 1, the architecture includes: an evolved UMTSterrestrial radio access network (E-UTRAN), which is adapted toimplement all radio-related functions of the evolved network; a mobilitymanagement entity (MME), which is responsible for the mobilitymanagement of the control plane, including user context management andmobility state management as well as assignment of temporary user IDs; aserving gateway (SGW), which is a user plane anchor point between 3GPPaccess networks, and adapted to terminate an interface of the E-UTRAN;and a packet data network gateway (PGW), which is a user plane anchorpoint between a 3GPP access network and a non-3GPP access network, andadapted to terminate an interface with an external packet data network(PDN).

A UMTS terrestrial radio access network (UTRAN) and a GSM/EDGE radioaccess network (GERAN) are adapted to implement all radio-relatedfunctions in an existing GPRS/UMTS network. A serving GPRS supportingnode (SGSN) is adapted to implement routing and forwarding, mobilitymanagement, session management, user information storage, and otherfunctions in the GPRS/UMTS network.

A 1x circuit switched (CS) domain access network is adapted to implementradio-related functions in the CDMA2000 1x network. A 1x CS mobileswitching center (MSC) is mainly adapted to provide mobility managementand switching functions for mobile users, and realize the interworkingbetween mobile users as well as between mobile users and fixed users. Aninterworking solution function (IWS) is adapted to implement a functionof exchanging and forwarding 1x CS signaling, so as to encapsulate 1x CSsignaling from the 1x CS MSC and send the encapsulated 1x CS signalingto a user equipment (UE) through the 3GPP PS network; or the UE sendsencapsulated 1x CS signaling to the IWS through the 3GPP PS network, andthe IWS forwards the encapsulated 1x CS signaling to the 1x CS MSC. TheIWS is also described as a 1x CS IWS.

In order to ensure the interworking between the 3GPP PS network and theoriginal CS network, a technology for handing over a voice over IP(VoIP) service in the 3GPP PS network to the CDMA2000 1x network hasbeen proposed in the prior art. FIG. 2 is a signaling flow chart of aprocedure for handing over a VoIP service of a UE from a 3GPP PS networkto a CDMA2000 1x network in the prior art. Referring to FIG. 2, theprocedure is as follows.

(1) A VoIP session exists in the 3GPP PS network.

(2) An access network of the 3GPP PS network decides to hand over to theCDMA2000 1x. The access network of the 3GPP PS network may be anE-UTRAN, a GERAN, or a UTRAN.

(3) The access network of the 3GPP PS network sends a relocationindication to notify the UE to perform an inter-system handover.

(4) The UE sends a 1x Origination message to a 1x CS IWS through the3GPP PS network. That is, the UE sends the 1x Origination message to theaccess network of the 3GPP PS network, and the access network of the3GPP PS network encapsulates the 1x Origination message into an UplinkCDMA2000 Tunnel message and sends the Uplink CDMA2000 Tunnel message toa mobility management network element of the 3GPP PS network. For theGERAN/UTRAN network, the mobility management network element of the 3GPPPS network is an SGSN; and for the E-UTRAN, the mobility managementnetwork element of the 3GPP PS network is an MME. After receiving theUplink CDMA2000 Tunnel message, the mobility management network elementof the 3GPP PS network acquires the 1x Origination message from theUplink CDMA2000 Tunnel message, and sends the 1x Origination message tothe 1x CS IWS.

(5) The IWS sends a CM Service Request message to a 1x CS MSC.

(6) The MSC sends an Assignment Request message to the IWS.

(7) The IWS sends a Handoff Direction message to the UE through the 3GPPPS network. That is, the IWS sends the Handoff Direction message to themobility management network element of the 3GPP PS network; the mobilitymanagement network element of the 3GPP PS network sends a DownlinkCDMA2000 Tunnel message (the Handoff Direction message is encapsulatedin the message) to the access network of the 3GPP PS network; and theaccess network of the 3GPP PS network forwards the Handoff Directionmessage to the UE.

(8) The UE is handed over to the CDMA 1x network, and a traffic channelacquisition (TCC) procedure is performed to obtain a traffic channel.

(9) The UE sends a 1x Handoff Complete message to the CDMA2000 1x accessnetwork.

(10) The CDMA2000 1x access network sends a Handoff Complete message oran Assignment Complete message to the MSC.

(11) A voice call is established in the CDMA2000 1x network.

It is known from the above procedure that, in the current mechanism forthe handover from the 3GPP PS network to the CDMA2000 1x network, whenthe UE is handed over from the 3GPP PS network to the CDMA2000 1xnetwork, no mechanism is provided for processing resources in the PSnetwork related to the UE. In addition, the same problem also occurswhen the UE is handed over from the PS network to other CS networkssimilar to the CDMA2000 1x network.

SUMMARY

Accordingly, an embodiment of the present invention provides a methodfor processing resource so as to process resources of a UE in a PSnetwork when the UE is handed over from the PS network to a CS network.The method is as follows.

A mobility management network element in a PS network receives a ReleaseRequest message sent by an access network of the PS network or a HandoffComplete message sent by a CS network when a UE is handed over from thePS network to the CS network, and then processes resources of the UE inthe PS network.

Through the method for processing resource provided by the embodimentsof the present invention, the mobility management network element of thePS network initiates processing of the resources of the UE in the PSnetwork upon receiving the Release Request message sent by the accessnetwork of the PS network or the Handoff Complete message sent by the CSnetwork, so that the processing of the resources of the UE in the PSnetwork is achieved when the UE is handed over from the PS network tothe CS network.

An embodiment of the present invention further provides a communicationsystem so as to process resources of a UE in a PS network when the UE ishanded over from the PS network to a CS network.

The communication system includes a mobility management network elementof a PS network and an access network of the PS network, wherein when aUE is handed over from the PS network to a CS network, the accessnetwork of the PS network is adapted to send a Release Request messageto the mobility management network element of the PS network, and themobility management network element of the PS network is adapted toreceive the Release Request message sent by the access network of the PSnetwork and process resources of the UE in the PS network.

Through the communication system provided by the embodiments of thepresent invention, the access network of the PS network sends a ReleaseRequest message to the mobility management network element of the PSnetwork, and the mobility management network element of the PS networkinitiates processing of the resources of the UE in the PS network uponreceiving the Release Request message sent by the access network of thePS network, so that the processing of the resources of the UE in the PSnetwork is achieved when the UE is handed over from the PS network tothe CS network.

An embodiment of the present invention further provides anothercommunication system so as to process resources of a UE in a PS networkwhen the UE is handed over from the PS network to a CS network.

The communication system includes a mobility management network elementof a PS network and a CS network. When a UE is handed over from the PSnetwork to the CS network, the CS network is adapted to send a HandoffComplete message to the mobility management network element of the PSnetwork; and the mobility management network element of the PS networkis adapted to receive the Handoff Complete message sent by the CSnetwork and process resources of the UE in the PS network afterreceiving the Handoff Complete message.

Through the communication system provided by the embodiment of thepresent invention, the CS network sends a Handoff Complete message tothe mobility management network element of the PS network, and themobility management network element of the PS network initiatesprocessing of the resources of the UE in the PS network upon receivingthe Handoff Complete message sent by the CS network, so that theprocessing of the resources of the UE in the PS network is achieved whenthe UE is handed over from the PS network to the CS network.

An embodiment of the present invention further provides a mobilitymanagement network element in a PS network so as to process resources ofa UE in a PS network when the UE is handed over from the PS network to aCS network.

The mobility management network element includes a receiving unit and aresource processing unit. The receiving unit is adapted to receive aRelease Request message sent by an access network of the PS network or aHandoff Complete message sent by a CS network when a UE is handed overfrom the PS network to the CS network. The resource processing unit isadapted to process resources of the UE in the PS network after thereceiving unit receives the Release Request message sent by the accessnetwork of the PS network or the Handoff Complete message sent by the CSnetwork.

Through the mobility management network element provided by theembodiment of the present invention, the receiving unit receives aRelease Request message sent by the access network of the PS network ora Handoff Complete message sent by the CS network when the UE is handedover from the PS network to the CS network, and the resource processingunit initiates processing of the resources of the UE in the PS networkafter the receiving unit receives the Release Request message sent bythe access network of the PS network or the Handoff Complete messagesent by the CS network, so that the processing of the resources of theUE in the PS network is achieved when the UE is handed over from the PSnetwork to the CS network.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 shows interworking architecture of a 3GPP PS network and aCDMA2000 1x network in a CDMA network;

FIG. 2 is a signaling flow chart of a procedure for handing over a VoIPservice of a UE from a 3GPP PS network to a CDMA2000 1x network;

FIG. 3 is a flow chart of a method for processing resource according toan embodiment of the present invention;

FIG. 4 is a flow chart of another method for processing resourceaccording to another embodiment of the present invention;

FIG. 5 is a flow chart of another method for processing resourceaccording to still another embodiment of the present invention;

FIG. 6 is a flow chart of another method for processing resourceaccording to still another embodiment of the present invention;

FIG. 7 is a signaling flow chart of a method for processing resourcewhen a UE is handed over from a PS network to a CDMA2000 1x networkaccording to an embodiment of the present invention;

FIG. 8 is a signaling flow chart of a method for processing resourcewhen a UE is handed over from a PS network to a CDMA2000 1x networkaccording to another embodiment of the present invention;

FIG. 9 is a signaling flow chart of a method for processing resourcewhen a UE is handed over from a PS network to a CDMA2000 1x networkaccording to still another embodiment of the present invention;

FIG. 10 is a structural view of a communication system according to anembodiment of the present invention;

FIG. 11 is a structural view of a communication system according toanother embodiment of the present invention;

FIG. 12 is a structural view of a mobility management network element ina PS network according to an embodiment of the present invention; and

FIG. 13 is a structural view of a mobility management network element ina PS network according to another embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In embodiments of the present invention, for the GERAN/UTRAN network,the mobility management network element of the PS network may be anSGSN; and for the E-UTRAN, the mobility management network element ofthe PS network is an MME.

In the embodiments of the present invention, the CS network to which theUE is handed over from the PS network may be a CDMA2000 1x network, aGSM network, or other CS networks.

FIG. 3 is a flow chart of a method for processing resource according toan embodiment of the present invention. Referring to FIG. 3, the methodis as follows.

In Step 31, when a UE is handed over from a PS network to a CS network,a mobility management network element of the PS network receives aRelease Request message sent by an access network of the PS network.

In Step 32, the mobility management network element of the PS networkprocesses resources of the UE in the PS network.

FIG. 4 is a flow chart of a method for processing resource according toanother embodiment of the present invention. Referring to FIG. 4, themethod is as follows:

In Step 41, a mobility management network element in a PS network sendsa Handoff Direction message to an access network of the PS network.

In Step 42, the access network of the PS network sends a Release Requestmessage to the mobility management network element of the PS networkafter receiving the Handoff Direction message.

In Step 43, the mobility management network element of the PS networkreceives the Release Request message sent by the access network of thePS network.

In Step 44, the mobility management network element of the PS networkprocesses resources of a UE in the PS network.

In this embodiment, the access network of the PS network determines thatthe UE is handed over according to the received Handoff Directionmessage sent by the mobility management network element of the PSnetwork, and then actively initiates a Release Request message, so thatthe mobility management network element of the PS network processes theresources of the UE in the PS network.

FIG. 5 is a flow chart of a method for processing resource according tostill another embodiment of the present invention. Referring to FIG. 5,the method is as follows.

In Step 51, a mobility management network element in a PS network sendsa Handoff Direction message to a UE through an access network of the PSnetwork.

In Step 52, the UE sends a Radio Resource Control (RRC) Release Requestmessage to the access network of the PS network after receiving theHandoff Direction message. The RRC Release Request message may beadapted to indicate the access network of the PS network to release anRRC connection. The RRC Release Request message sent by the UE may alsocontain indication information indicating that the RRC Release Requestis caused by handing over the UE to a CS network. For example, the UEcarries a “Cause” information element (IE) in the message, and a valueof the IE is set to “Handover Triggered”; or the UE carries a “HandoverTriggered Indicator” IE in the message.

In Step 53, the access network of the PS network sends a Release Requestmessage to the mobility management network element of the PS networkafter receiving the RRC Release Request message.

In Step 54, the mobility management network element of the PS networkreceives the Release Request message sent by the access network of thePS network.

In Step 55, the mobility management network element of the PS networkprocesses resources of the UE in the PS network.

In this embodiment, upon receiving the Handoff Direction message sent bythe network side, i.e., when the UE has finished the CS network accessestablishment through the PS network and is ready to be handed over tothe CS network, the UE actively initiates a release procedure, and sendsan RRC Release Request message to the access network of the PS networkto indicate the network side that the resources of the UE in the PSnetwork can be processed; the access network of the PS network sends theRelease Request message to the mobility management network element ofthe PS network after receiving the RRC Release Request message sent bythe UE, so that the mobility management network element of the PSnetwork processes the resources of the UE in the PS network.

In the Steps 31, 42, and 53 of the above embodiments, the ReleaseRequest message sent by the access network of the PS network to themobility management network element of the PS network may containindication information to indicate that the Release Request is caused byhanding over the UE to the CS network, which is adapted to indicate thatthis Release Request is caused by handing over the UE to the CS network.For example, the access network of the PS network may carry a “Cause” IEin the Release Request message, and a value of the IE is set to“Handover Triggered”; or the access network of the PS network may carrya “Handover Triggered Indicator” IE in the Release Request message.

After receiving the Release Request message sent by the access networkof the PS network, if the mobility management network element of the PSnetwork finds that the message carries the indication informationindicating that the Release Request is caused by handing over the UE tothe CS network, the mobility management network element of the PSnetwork processes the resources of the UE in the PS network.

FIG. 6 is a flow chart of a method for processing resource according tostill another embodiment of the present invention. Referring to FIG. 6,the method is as follows.

In Step 61, when a UE is handed over from a PS network to a CS network,a mobility management network element of the PS network receives aHandoff Complete message sent by the CS network.

In Step 62, the mobility management network element of the PS networkprocesses resources of the UE in the PS network.

In Step 61, the process in which the mobility management network elementof the PS network receives the Handoff Complete message sent by the CSnetwork may be as follows according to a specific configuration ofnetwork equipments.

If an IWS between the CS network and the PS network is integrated withan access network element of the CS network, the access network elementof the CS network sends the Handoff Complete message to the mobilitymanagement network element of the PS network after receiving the HandoffComplete message sent by the UE.

Alternatively, if the IWS between the CS network and the PS network isintegrated with the mobility management network element of the PSnetwork, a mobility management network element of the CS network sends aClear Command message to the mobility management network element of thePS network after receiving the Handoff Complete message sent by theaccess network element of the CS network. In this case, after themobility management network element of the PS network receives the ClearCommand message, the IWS in the mobility management network element ofthe PS network may convert the Clear Command message into a HandoffComplete message; or after receiving the Clear Command message, themobility management network element of the PS network may consider thatthe Handoff Complete message is received and perform subsequentprocessing.

Alternatively, if the IWS between the CS network and the PS network isan independent network element, the mobility management network elementof the CS network sends a Clear Command message to the IWS afterreceiving the Handoff Complete message sent by the access networkelement of the CS network, and the IWS sends the Handoff Completemessage to the mobility management network element of the PS network.

Alternatively, if the IWS between the CS network and the PS network isintegrated with the mobility management network element of the CSnetwork, the mobility management network element of the PS networkreceives the Handoff Complete message sent by the mobility managementnetwork element of the CS network.

For a CDMA2000 1x network, the mobility management network element ofthe CS network may be a 1x CS MSC.

In this embodiment, when the UE is handed over from the PS network tothe CS network, the mobility management network element of the PSnetwork determines that the UE is successfully handed over to the CSnetwork according to the received Handoff Complete message sent by theCS network, and actively initiates processing of the resources of the UEin the PS network.

In Steps 32, 44, 55, and 62 of the above embodiments, the mobilitymanagement network element of the PS network may process the resourcesof the UE in the PS network in one of the following manners.

The mobility management network element of the PS network initiates animplicit user detachment procedure (i.e., the network side does not needto send a Detach message to notify the UE to detach after the UE isdetached from the network side) to detach the UE from the PS network.

Alternatively, the mobility management network element of the PS networkdoes not initiate the detachment of the UE, but reserves all bearers ofthe UE in the PS network, and indicates an SGW to suspend the bearers.

Alternatively, the mobility management network element of the PS networkdoes not initiate the detachment of the UE, but initiates delete bearerprocedure(s) to delete one part of the bearers and reserves the otherpart of bearers according to different bearer types, and indicates theSGW to suspend the reserved bearers. For example, for Guaranteed BitRate (GBR) bearers, the mobility management network element of the PSnetwork initiates delete bearer procedure(s) to delete the GBR bearers;and for non-GBR bearers, the mobility management network element of thePS network reserves the non-GBR bearers, and indicates the SGW tosuspend the non-GBR bearers. Dedicated network resources need to beallocated to the GBR bearers, but do not need to be allocated to thenon-GBR bearers, as the non-GBR bearers may share network resources withthe other part of bearers. In this way, as the GBR bearers are deletedin time, the dedicated network resources may be released in time. Thenon-GBR bearers, which may share network resources with the other partof bearers due to no waste of network resources, are suspended.

Alternatively, for VoIP bearers, the mobility management network elementof the PS network initiates delete bearer procedure(s) to delete theVoIP bearers; for bearers other than the VoIP bearers, the mobilitymanagement network element of the PS network reserves the bearers otherthan the VoIP bearers, and indicates the SGW to suspend the bearersother than the VoIP bearers. In this way, original voice bearers of theUE in the PS network may be released in time, and other non-voicebearers may be reserved and suspended. Thus, after returning to the PSnetwork, the UE can continuously provide services to the user.

In this embodiment to the present invention, when the mobilitymanagement network element of the PS network needs to delete one part ofthe bearers while reserving the other part of bearers according todifferent bearer types, one of the following manners may also be used.

(1) The mobility management network element of the PS network mayindicate the SGW to suspend all bearers of the UE; and the mobilitymanagement network element of the PS network reserves one part of thebearers (for example, non-GBR bearers) and initiating a delete bearerprocedure to delete the other part of bearers (for example, GBR bearers)according to different bearer types.

(2) The mobility management network element of the PS network deletesone part of the bearers (for example, GBR bearers) and reserves theother part of bearers (for example, non-GBR bearers) according todifferent bearer types, and indicates the SGW to suspend the reservedbearers; the SGW suspends the reserved bearers and deletes theunreserved bearers after receiving a Suspend Bearer message (that is,the SGW deletes the unsuspended bearers, for example, the SGW deletesthe GBR bearers).

(3) The mobility management network element of the PS network deletesone part of the bearers (for example, GBR bearers) and reserves theother part of bearers (for example, non-GBR bearers) according todifferent bearer types, and indicates the SGW to suspend all bearers ofthe UE; the SGW deletes one part of the bearers (for example, GBRbearers) and suspends the reserved bearers (for example, non-GBRbearers) according to different bearer types after receiving a SuspendBearer message. In this manner, the SGW and the mobility managementnetwork element are required to have the same bearer processing rule.

(4) The mobility management network element of the PS network deletesone part of the bearers and reserves the other part of bearers accordingto different bearer types, and indicates the SGW to suspend the reservedbearers and delete the unreserved bearers. The manner 4) may beimplemented in one of the following four methods.

Method 1: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains IDs of bearers to be suspended and IDs ofbearers to be deleted as well as states of the bearers. The states ofthe bearers to be suspended are set to “suspend”, and the states of thebearers to be deleted are set to “delete.” After receiving the UpdateBearer Request message, the SGW suspends the bearers corresponding tothe IDs of the bearers in the “suspend” state, and delete the bearerscorresponding to the IDs of the bearers in the “delete” state.

In this method, the content carried by the Update Bearer Request messageis, for example, as follows:

-   -   Bearer ID 1, Suspend    -   Bearer ID 2, Suspend    -   Bearer ID 3, Delete    -   Bearer ID 4, Delete.

Method 2: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains a suspend list of the IDs of the bearers to besuspended and a delete list of the IDs of the bearers to be deleted.After receiving the Update Bearer Request message, the SGW suspends thebearers corresponding to the suspend list, and deletes the bearerscorresponding to the delete list.

In this method, the content carried by the Update Bearer Request messageis, for example, as follows:

-   -   Suspend List:    -   Bearer ID 1    -   Bearer ID 2    -   Delete List:    -   Bearer ID 3    -   Bearer ID 4.

Method 3: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains a suspend list of the IDs of the bearers to besuspended and a delete list of the IDs of the bearers to be deleted.After receiving the Suspend Bearer Request message, the SGW sets statesof the bearers corresponding to the suspend list to “suspend”, anddeletes the bearers corresponding to the delete list.

Method 4: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains an ID of the UE and a delete list of the IDs ofthe bearers to be deleted. After receiving the Suspend Bearer Requestmessage, the SGW deletes bearers corresponding to the delete list, andsuspends the other part of bearers.

The mobility management network element of the PS network indicates theSGW to suspend the bearers to be suspended in the following fourmanners:

Manner 1: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains IDs of bearers to be suspended and states ofthe bearers, and the states of the bearers are set to “suspend.” Afterreceiving the Update Bearer Request message, the SGW suspends thebearers corresponding to the IDs of bearers.

Manner 2: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains the ID of the UE and states of the bearers, andthe states of the bearers are set to “suspend.” After receiving theUpdate Bearer Request message, the SGW suspends all bearers of the UE.

Manner 3: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains IDs of bearers to be suspended. After receivingthe Suspend Bearer Request message, the SGW sets states of the bearerscorresponding to the IDs of bearers to “suspend.”

Manner 4: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message carries the ID of the UE. After receiving the SuspendBearer Request message, the SGW sets states of all bearers of the UE to“suspend.”

After the SGW suspends the bearers, the SGW subsequently receivesdownlink data packets on the suspended bearers but does not triggerpaging. The SGW may buffer these downlink data packets, and may alsorelease resources used by the suspended bearers between the SGW and adownlink user plane network element, for example, release downlink TEIDsused by the suspended bearers. For example, for an E-UTRAN network, theSGW releases resources between the SGW and an eNodeB; for a UTRANnetwork, the SGW releases resources between the SGW and a radio networkcontroller (RNC) or a 3G SGSN; and for a GERAN network, the SGW releasesresources between the SGW and a 2G SGSN.

A procedure for handing over a UE from a PS network to a CDMA2000 1xnetwork is taken for example in the following detailed illustration.Basic processes and processing mechanisms for other CS networks such asa GSM CS network are the same or similar, so the details will not bedescribed herein again.

FIG. 7 is a signaling flow chart of a method for processing resourcewhen a UE is handed over from a PS network to a CDMA2000 1x networkaccording to an embodiment of the present invention. Referring to FIG.7, the method is specifically as follows.

In Step 71, a VoIP session exists in a PS network.

In Step 72, an access network of the PS network decides to hand over toa CDMA2000 1x network. The access network of the PS network may be anE-UTRAN, a GERAN, or a UTRAN.

In Step 73, the access network of the PS network sends a relocationindication to notify the UE to perform an inter-system handover.

In Step 74, the UE sends a 1x Origination message to a 1x CS IWS throughthe PS network. That is, the UE sends the 1x Origination message to theaccess network of the PS network, and the access network of the PSnetwork sends an Uplink CDMA2000 Tunnel message (the 1x Originationmessage is encapsulated in the message) to a mobility management networkelement of the PS network (for the GERAN/UTRAN network, the mobilitymanagement network element of the PS network is an SGSN; and for theE-UTRAN, the mobility management network element of the PS network is anMME). After receiving the Uplink CDMA2000 Tunnel message, the mobilitymanagement network element of the PS network acquires the 1x Originationmessage from the Uplink CDMA2000 Tunnel message, and sends the 1xOrigination message to the 1x CS IWS.

In Step 75, the IWS sends a CM Service Request message to a 1x CS MSC.

In Step 76, the MSC sends an Assignment Request message to the IWS.

In Step 77, the IWS sends a Handoff Direction message to the UE throughthe PS network. That is, the IWS sends the Handoff Direction message tothe mobility management network element of the PS network; the mobilitymanagement network element of the PS network sends a Downlink CDMA2000Tunnel message (the Handoff Direction message is encapsulated in themessage) to the access network of the PS network; and the access networkof the PS network forwards the Handoff Direction message to the UE.

In Step 78, the UE sends an RRC Release Request message to the accessnetwork of the PS network before being handed over to the CDMA 1xnetwork. The UE carries indication information in the RRC ReleaseRequest message, and the indication information is adapted to indicatethe access network of the PS network that the RRC connection release iscaused by a handover. For example, the UE carries a “Cause” IE in themessage, and a value of the IE is set to “Handover Triggered”; or the UEcarries a “Handover Triggered Indicator” IE in the message.

In Step 79, the access network of the PS network sends a release requestmessage to the mobility management network element of the PS networkafter receiving the RRC Release Request message. For the E-UTRANnetwork, the release request message is an S1 UE Context Release Requestmessage, and for the UTRAN/GERAN network, the release request message isan Iu Release Request message. The access network of the PS networkcarries indication information in the Release Request message, and theindication information is adapted to indicate the mobility managementnetwork element of the PS network that the Release Request is caused byhanding over the UE. For example, the access network of the PS networkcarries a “Cause” IE in the Release Request message, and a value of theIE is set to “Handover Triggered”; or the access network of the PSnetwork carries a “Handover Triggered Indicator” IE in the ReleaseRequest message.

In Step 710, the mobility management network element of the PS networkmanages resources of the UE in the PS network after receiving the abovemessage. The mobility management network element of the PS network mayprocess the resources as follows.

(1) The mobility management network element of the PS network initiatesan implicit user detachment procedure to detach the UE from the PSnetwork. When the UE is detached from the network, bearers are deletedfrom the PS network. At this time, as shown in FIG. 7, the mobilitymanagement network element of the PS network only sends a Delete BearerRequest message to the SGW. The SGW interacts with a PDN GW to deletethe bearers related to the UE.

(2) The mobility management network element of the PS network does notdetach the UE (that is, reserves an MM context of the UE). For GBRbearers, the mobility management network element of the PS networkinitiates a delete bearer procedure to delete the bearers, that is,sends a Delete Bearer Request message to the SGW; and for non-GBRbearers, the mobility management network element of the PS networkreserves these bearers, but indicates the SGW to suspend these bearers.

(3) The mobility management network element of the PS network does notdetach the UE (that is, reserves the MM context of the UE). For VoIPbearers, the mobility management network element of the PS networkinitiates a delete bearer procedure to delete the bearers, that is,sends a Delete Bearer Request message to the SGW; and for the other partof bearers, the mobility management network element of the PS networkreserves these bearers, but indicates the SGW to suspend these bearers.

(4) The mobility management network element of the PS network does notdetach the UE (that is, reserves the MM context of the UE). For thebearers, the mobility management network element of the PS networkreserves the bearers, but indicates the SGW to suspend the bearers.

The mobility management network element of the PS network may indicatethe SGW to suspend the bearers in the following methods.

(a) The mobility management network element of the PS network sends anUpdate Bearer Request message to the SGW. For each bearer to besuspended, the Update Bearer Request message carries an ID of the bearerand a state of the bearer. The mobility management network element ofthe PS network sets the state of the bearer to “suspend.”

(b) The mobility management network element of the PS network sends anUpdate Bearer Request message to the SGW. The message carries an ID ofthe UE and states of bearers. The mobility management network element ofthe PS network sets the states of the bearers to “suspend”, and the SGWsets states of all bearers of the UE to “suspend.”

(c) The mobility management network element of the PS network sends aSuspend Bearer Request message to the SGW. For each bearer to besuspended, the Suspend Bearer Request message carries an ID of thebearer. After receiving the Suspend Bearer Request message, the SGW setsa state of the bearer corresponding to the ID to “suspend.”

(d) The mobility management network element of the PS network sends aSuspend Bearer Request message to the SGW. The message carries the ID ofthe UE. After receiving the Suspend Bearer Request message, the SGW setsstates of all bearers of the UE to “suspend.”

In Step 711, the UE is handed over to the CDMA 1x network, and a TCCprocedure is performed to obtain a traffic channel.

In Step 712, the UE sends a 1x Handoff Complete message to the CDMA20001x access network.

In Step 713, the CDMA2000 1x access network sends a Handoff Completemessage or an Assignment Complete message to the MSC.

In Step 714, a voice call is established in the CDMA2000 1x network.

In this embodiment of the present invention, when the mobilitymanagement network element of the PS network needs to delete one part ofthe bearers and reserve the other part of bearers according to differentbearer types, one of the following manners may also be used.

(1) The mobility management network element of the PS network mayindicate the SGW to suspend all bearers of the UE; and the mobilitymanagement network element of the PS network reserves one part of thebearers (for example, non-GBR bearers) and initiates a delete bearerprocedure to delete the other part of bearers (for example, GBR bearers)according to different bearer types.

(2) The mobility management network element of the PS network deletesone part of the bearers (for example, GBR bearers) and reserves theother part of bearers (for example, non-GBR bearers) according todifferent bearer types, and indicates the SGW to suspend the reservedbearers; and the SGW suspends the reserved bearers and deletes theunreserved bearers after receiving a Suspend Bearer message (i.e., theSGW deletes the unsuspended bearers, for example, the SGW deletes theGBR bearers).

(3) The mobility management network element of the PS network deletesone part of the bearers (for example, GBR bearers) and reserves theother part of bearers (for example, non-GBR bearers) according todifferent bearer types, and indicates the SGW to suspend all bearers ofthe UE; and the SGW deletes one part of the bearers (for example, GBRbearers) and suspends the reserved bearers (for example, non-GBRbearers) according to different bearer types after receiving a SuspendBearer message. In this manner, the SGW and the mobility managementnetwork element are required to have the same bearer processing rule.

(4) The mobility management network element of the PS network deletesone part of the bearers and reserves the other part of bearers accordingto different bearer types, and indicates the SGW to suspend the reservedbearers and delete the unreserved bearers. The manner (4) may beimplemented in one of the following four methods.

Method 1: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains IDs of bearers to be suspended and IDs ofbearers to be deleted as well as states of the bearers. The states ofthe bearers to be suspended are set to “suspend”, and the states of thebearers to be deleted are set to “delete.” After receiving the UpdateBearer Request message, the SGW suspends the bearers corresponding tothe IDs of the bearers in the “suspend” state and delete the bearerscorresponding to the IDs of the bearers in the “delete” state.

Method 2: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains a suspend list of the IDs of the bearers to besuspended and a delete list of the IDs of the bearers to be deleted.After receiving the Update Bearer Request message, the SGW suspends thebearers corresponding to the suspend list, and deletes the bearerscorresponding to the delete list.

Method 3: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains a suspend list of the IDs of the bears to besuspended and a delete list of the IDs of the bearers to be deleted.After receiving the Suspend Bearer Request message, the SGW sets statesof the bearers corresponding to the suspend list to “suspend”, anddeletes the bearers corresponding to the delete list.

Method 4: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains an ID of the UE and a delete list of the IDs ofthe bearers to be deleted. After receiving the Suspend Bearer Requestmessage, the SGW deletes the bearers corresponding to the delete list,and suspends the other part of bearers.

Through the above embodiment, upon receiving the Handoff Directionmessage sent by the CDMA2000 1x access network, i.e., when the UE hasfinished the CDMA2000 1x network access establishment through the PSnetwork and is ready to be handed over to the CDMA2000 1x accessnetwork, the UE actively initiates a release procedure, and sends an RRCRelease Request message to the access network of the PS network toindicate the network side that the resources of the UE in the PS networkcan be processed; and the access network of the PS network sends theRelease Request message to the mobility management network element ofthe PS network after receiving the RRC Release Request message sent bythe UE, so that the mobility management network element of the PSnetwork processes the resources of the UE in the PS network.

FIG. 8 is a signaling flow chart of a method for processing resourcewhen a UE is handed over from a PS network to a CDMA2000 1x networkaccording to another embodiment of the present invention. Referring toFIG. 8, the method is as follows:

Steps 81-87 are corresponding to Steps 71-77 in the previous embodimentrespectively.

In Step 88, the access network of the PS network sends a release messageto the mobility management network element of the PS network afterreceiving the Downlink CDMA2000 Tunnel message (the Handoff Directionmessage is encapsulated in the message) sent by the mobility managementnetwork element of the PS network, that is, after receiving the HandoffDirection message sent by the mobility management network element of thePS network. For the E-UTRAN network, the release message is an S1 UEContext Release Request message, and for the UTRAN/GERAN network, therelease message is an Iu Release Request message. The access network ofthe PS network carries indication information in the Release Requestmessage, and the indication information is adapted to indicate themobility management network element of the PS network that the ReleaseRequest is caused by handing over the UE. For example, the accessnetwork of the PS network carries a “Cause” IE in the Release Requestmessage, and a value of the IE is set to “Handover Triggered”; or theaccess network of the PS network carries a “Handover TriggeredIndicator” IE in the Release Request message.

Steps 89-813 are corresponding to Steps 710-714 in the previousembodiment respectively.

In this embodiment, the access network of the PS network determines thatthe UE is handed over according to the received Handoff Directionmessage sent by the mobility management network element of the PSnetwork, and then actively initiates a Release Request message, so thatthe mobility management network element of the PS network processes theresources of the UE in the PS network.

FIG. 9 is a signaling flow chart of a method for processing resourcewhen a UE is handed over from a PS network to a CDMA2000 1x networkaccording to still another embodiment of the present invention.Referring to FIG. 9, the method is as follows.

Steps 91-97 are corresponding to Steps 71-77 in the above embodimentrespectively.

Steps 98-911 are corresponding to Steps 711-714 in the above embodimentrespectively.

In Step 912, after the UE is handed over to the CDMA 2000 1x network,the 1x CS MSC receives an Assignment Complete message (shown in thefigure) sent by a 1x CS access network element, or receives a 1x HandoffComplete message (not shown in the figure, and capable of replacing theAssignment Complete message) sent by the 1x CS access network element,and then sends a Clear Command message to the IWS.

In Step 913, the IWS sends a Handoff Complete message to the mobilitymanagement network element of the PS network after receiving the ClearCommand message.

In Step 914, after receiving the Handoff Complete message sent by theIWS, the mobility management network element of the PS networkdetermines that the UE is handed over, and then manages resources of theUE in the PS network. The processing method used by the mobilitymanagement network element of the PS network for managing the resourcesof the UE in the PS network is the same as that in Step 710, so thedetails will not be described herein again.

In this embodiment, when the UE is handed over from the PS network tothe CS network, the mobility management network element of the PSnetwork determines that the UE is successfully handed over to the CSnetwork according to the received Handoff Complete message sent by theCS network, and actively initiates processing of the resources of the UEin the PS network, so that the processing of the resources of the UE inthe PS network is achieved.

In the embodiment shown in FIG. 9, the IWS is an independent networkelement, which mainly implements a function of exchanging and forwarding1x CS signaling, so as to encapsulate 1x CS signaling from the 1x CS MSCand send the encapsulated 1x CS signaling to the UE through the PSnetwork; or the UE sends encapsulated 1x CS signaling to the IWS throughthe PS network, and the IWS forwards the encapsulated 1x CS signaling tothe 1x CS MSC. In actual implementations, the function of the IWS mayalso be integrated with other network elements in the network to form anintegrated network element. At this time, in the embodiment shown inFIG. 9, in Steps 912 and 913, the process in which the mobilitymanagement network element of the PS network receives the HandoffComplete message sent by the CS network may be as follows.

(1) If the IWS is integrated with the 1x CS access network element, theIWS/1x CS access network element sends a Handoff Complete message or anAssignment Complete message to the mobility management network elementof the PS network after receiving the 1x Handoff Complete message sentby the UE. In the embodiment of the present invention, the HandoffComplete message and the Assignment Complete message are only differentin name, but have the same function for indicating that the handover iscompleted, and may both be considered as a Handoff Complete message.

(2) If the 1x CS IWS is integrated with the mobility management networkelement of the PS network, the 1x CS MSC sends a Clear Command messageto the 1x CS IWS or the mobility management network element of the PSnetwork after receiving the Handoff Complete message sent by the 1x CSaccess network element. In this case, after the integrated networkelement receives the Clear Command message, the IWS in the integratednetwork element may convert the Clear Command message into a HandoffComplete message; or after receiving the Clear Command message, theintegrated network element may consider that a Handoff Complete messageis received, and perform subsequent processing.

(3) If the 1x CS IWS is integrated with the 1x CS MSC, the 1x CS IWS/1xCS MSC sends a Handoff Complete message to the mobility managementnetwork element of the PS network after receiving the Handoff Completemessage sent by the 1x CS access network element.

The method for processing resources of a UE in a PS network when the UEis handed over from the PS network to a CS network has been detailedabove. A communication system and a mobility management network elementin a PS network, which are adapted to process resources of a UE in thePS network when the UE is handed over from the PS network to a CSnetwork, will be described in the following. Various processing measuresas well as the detailed description of the features in the above methodare applicable to the communication system and the mobility managementnetwork element in a PS network described in the following.

FIG. 10 is a structural view of a communication system according to anembodiment of the present invention. Referring to FIG. 10, thecommunication system includes a mobility management network element 101in a PS network and an access network 103 of the PS network. When a UEis handed over from the PS network to a CS network, the access network103 of the PS network is adapted to send a Release Request message tothe mobility management network element of the PS network; and themobility management network element 101 in the PS network is adapted toreceive the Release Request message sent by the access network of the PSnetwork, and process resources of the UE in the PS network.

For a GERAN/UTRAN network, the mobility management network element ofthe PS network may be an SGSN; and for an E-UTRAN, the mobilitymanagement network element of the PS network may be an MME. Accordingly,the access network of the PS network may also be corresponding to accessnetworks in various PS networks.

The specific procedure for handing over the UE from the PS network tothe CS network is as described in the method embodiments of FIGS. 7 and8, and the details will not be described herein again. Here, the accessnetwork of the PS network may send the Release Request message to themobility management network element of the PS network after receiving aHandoff Direction message sent by the mobility management networkelement of the PS network, or send the Release Request message to themobility management network element of the PS network after receiving anRRC Release Request message sent by the UE. The RRC Release Requestmessage may be sent by the UE to the access network of the PS networkafter the UE receives the Handoff Direction message. The RRC ReleaseRequest message may further contain indication information indicatingthat the RRC Release Request is caused by handing over the UE to the CSnetwork. For example, the UE carries a “Cause” IE in the message, and avalue of the IE is set to “Handover Triggered”; or the UE carries a“Handover Triggered Indicator” IE in the message. The access network ofthe PS network may also be adapted to carry indication information inthe Release Request message sent to the mobility management networkelement of the PS network, and the indication information is adapted toindicate that the Release Request is caused by handing over the UE tothe CS network. For example, the access network of the PS networkcarries a “Cause” IE in the Release Request message, and a value of theIE is set to “Handover Triggered”; or the access network of the PSnetwork carries a “Handover Triggered Indicator” IE in the ReleaseRequest message.

The mobility management network element of the PS network may processthe resources of the UE in the PS network through one of the followingmanners.

(1) The mobility management network element of the PS network initiatesan implicit user detachment procedure to detach the UE from the PSnetwork. When the UE is detached from the network, the bearers aredeleted from the PS network.

(2) The mobility management network element of the PS network does notdetach the UE (that is, reserves an MM context of the UE). For GBRbearers, the mobility management network element of the PS networkinitiates a delete bearer procedure to delete the bearers; and fornon-GBR bearers, the mobility management network element of the PSnetwork reserves the bearers, but indicates the SGW to suspend thebearers. The mobility management network element of the PS network mayindicate the SGW to suspend the bearers in the following methods.

(a) The mobility management network element of the PS network sends anUpdate Bearer Request message to the SGW. For each bearer to besuspended, the Update Bearer Request message carries an ID of the bearerand a state of the bearer. The mobility management network element ofthe PS network sets the state of the bearer to “suspend.”

(b) The mobility management network element of the PS network sends aSuspend Bearer Request message to the SGW. For each bearer to besuspended, the Suspend Bearer Request message carries an ID of thebearer.

After receiving indication of bearer suspend, the SGW sets a state ofthe bearer to “suspend.” After receiving downlink data packets on thebearer, the SGW does not trigger paging. The SGW may buffer the downlinkdata packets, or release resources used by the suspended bearers betweenthe SGW and a downlink user plane network element (for example, the SGWreleases downlink TEIDs used by the suspended bearers). For example, foran E-UTRAN network, the SGW releases resources between the SGW and aneNodeB; for a UTRAN network, the SGW releases resources between the SGWand an RNC or a 3G SGSN; and for a GERAN network, the SGW releasesresources between the SGW and a 2G SGSN.

(3) The mobility management network element of the PS network does notdetach the UE (that is, reserves the MM context of the UE). For VoIPbearers, the mobility management network element of the PS networkinitiates a delete bearer procedure to delete the bearers; and for theother part of bearers, the mobility management network element of the PSnetwork reserves the bearers, but indicates the SGW to suspend thebearers.

(4) The mobility management network element of the PS network does notdetach the UE (that is, reserves the MM context of the UE). For thebearers, the mobility management network element of the PS networkreserves these bearers, but indicates the SGW to suspend the bearers.The mobility management network element of the PS network may indicatethe SGW to suspend the bearers in the following methods.

(a) The mobility management network element of the PS network sends anUpdate Bearer Request message to the SGW. For each bearer to besuspended, the Update Bearer Request message carries an ID of the bearerand a state of the bearer. The mobility management network element ofthe PS network sets the state of the bearer to “suspend.”

(b) The mobility management network element of the PS network sends anUpdate Bearer Request message to the SGW. The message carries an ID ofthe UE and states of bearers. The mobility management network element ofthe PS network sets the states of the bearers to “suspend”, and the SGWsets states of all bearers of the UE to “suspend.”

(c) The mobility management network element of the PS network sends aSuspend Bearer Request message to the SGW. For each bearer to besuspended, the Suspend Bearer Request message carries an ID of thebearer. After receiving the Suspend Bearer Request message, the SGW setsa state of the bearer corresponding to the ID of the bearer to“suspend.”

(d) The mobility management network element of the PS network sends aSuspend Bearer Request message to the SGW. The message carries the ID ofthe UE. After receiving the Suspend Bearer Request message, the SGW setsstates of all bearers of the UE to “suspend.”

Note: The mobility management network element of the PS network may alsoindicate the SGW to suspend all bearers of the UE; and the mobilitymanagement network element of the PS network reserves one part of thebearers (for example, non-GBR bearers) and initiates a delete bearerprocedure to delete the other part of bearers (for example, GBR bearersor VoIP bearers) according to different bearer types.

The mobility management network element of the PS network deletes onepart of the bearers and reserves the other part of bearers (for example,non-GBR bearers) according to different bearer types, and indicates theSGW to suspend the reserved bearers; and the SGW suspends the reservedbearers and deletes the unreserved bearers after receiving a SuspendBearer message (that is, the SGW deletes the unsuspended bearers, forexample, the SGW deletes the GBR bearers or VoIP bearers).

The mobility management network element of the PS network deletes onepart of the bearers and reserves the other part of bearers (for example,non-GBR bearers) according to different bearer types, and indicates theSGW to suspend the bearers (as described in the manner 4, the mobilitymanagement network element of the PS network sends a Suspend BearerRequest message to the SGW, and the Suspend Bearer Request messagecarries the ID of the UE); and the SGW suspends the reserved bearers(for example, non-GBR bearers) and deletes the unreserved bearers afterreceiving the Suspend Bearer message (that is, the SGW deletes theunsuspended bearers, for example, the SGW deletes the GBR bearers orVoIP bearers).

The mobility management network element of the PS network deletes onepart of the bearers and reserves the other part of bearers according todifferent bearer types, and indicates the SGW to suspend the reservedbearers and delete the unreserved bearers. One of the following fourmethods may be used.

Method 1: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains IDs of bearers to be suspended and IDs ofbearers to be deleted as well as states of the bearers. The states ofthe bearers to be suspended are set to “suspend”, and the states of thebearers to be deleted are set to “delete.” After receiving the UpdateBearer Request message, the SGW suspends the bearers corresponding tothe IDs of the bearers to be suspended, and delete the bearerscorresponding to the IDs of the bearers to be deleted.

Method 2: The mobility management network element of the PS networksends an Update Bearer Request message to the SGW. The Update BearerRequest message contains a suspend list of IDs of the bearers to besuspended and a delete list of IDs of the bearers to be deleted. Afterreceiving the Update Bearer Request message, the SGW suspends thebearers corresponding to the suspend list, and deletes the bearerscorresponding to the delete list.

Method 3: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains IDs of the bearers to be suspended and a deletelist of the IDs of the bearers to be deleted. After receiving theSuspend Bearer Request message, the SGW sets states of the bearerscorresponding to the IDs of the bearers to be suspended to “suspend”,and deletes the bearers corresponding to the delete list.

Method 4: The mobility management network element of the PS networksends a Suspend Bearer Request message to the SGW. The Suspend BearerRequest message contains an ID of the UE and a delete list of the IDs ofthe bearers to be deleted. After receiving the Suspend Bearer Requestmessage, the SGW deletes the bearers corresponding to the delete list,and suspends the other part of bearers.

The communication system may further include: a CS network, adapted tointeract with the mobility management network element of the PS network,provide radio resources necessary for handing over the UE, and send aHandoff Complete message to the mobility management network element ofthe PS network after the handover of the UE is completed. The mobilitymanagement network element of the PS network sends the Handoff Completemessage to the UE through the access network of the PS network. Specificimplementations are described in the following with reference to theembodiments corresponding to FIGS. 7 and 8.

Through the communication system provided by the embodiment of thepresent invention, the access network of the PS network sends a ReleaseRequest message to the mobility management network element of the PSnetwork, and the mobility management network element of the PS networkinitiates processing of the resources of the UE in the PS network uponreceiving the Release Request message sent by the access network of thePS network, so that the processing of the resources of the UE in the PSnetwork is achieved when the UE is handed over from the PS network to aCDMA2000 1x network.

FIG. 11 is a structural view of a communication system according toanother embodiment of the present invention. Referring to FIG. 11, thecommunication system includes a mobility management network element 111in a PS network and a CS network 113. When a UE is handed over from thePS network to the CS network, the CS network 113 is adapted to send aHandoff Complete message to the mobility management network element ofthe PS network; and the mobility management network element 111 in thePS network is adapted to receive the Handoff Complete message sent bythe CS network, and process resources of the UE in the PS network afterreceiving the Handoff Complete message.

For a GERAN/UTRAN network, the mobility management network element ofthe PS network may be an SGSN; and for an E-UTRAN, the mobilitymanagement network element of the PS network may be an MME. The CSnetwork may be a CDMA 2000 1x network, a GSM CS network, or the like.

The specific procedure for handing over the UE from the PS network tothe CS network is as shown in the method embodiment of FIG. 9, and thedetails will not be described herein again. Here, the mobilitymanagement network element of the PS network processes the resources ofthe UE in the PS network after receiving the Handoff Complete message.

Further, the communication system may further include an IWS networkelement between the CS network and the PS network, and the CS networkmay further include an access network element and a mobility managementnetwork element. For example, in a CDMA 2000 1x network, the accessnetwork element may be a 1x CS access network element, and the mobilitymanagement network element may be a 1x CS MSC.

The IWS network element mainly implements a function of exchanging andforwarding 1x CS signaling, so as to encapsulate 1x CS signaling fromthe 1x CS MSC and send the encapsulated 1x CS signaling to the UEthrough the PS network; or the UE sends encapsulated 1x CS signaling tothe IWS through the PS network, and the IWS forwards the encapsulated 1xCS signaling to the 1x CS MSC. In specific implementations, the IWS maybe an independent network element, or be integrated with other networkelements in the network to form an integrated network element, which mayspecifically include the following circumstances.

(1) If the IWS network element is integrated with the access networkelement of the CS network, the integrated network element is adapted tosend the Handoff Complete message to the mobility management networkelement of the PS network after receiving the Handoff Complete messagesent by the UE.

(2) If the IWS network element is integrated with the mobilitymanagement network element of the PS network, the access network elementof the CS network is adapted to send the Handoff Complete message to themobility management network element of the CS network; and the mobilitymanagement network element of the CS network is adapted to send a ClearCommand message to the integrated network element after receiving theHandoff Complete message sent by the access network element of the CSnetwork.

(3) If the IWS between the CS network and the PS network is anindependent network element, the access network element of the CSnetwork is adapted to send the Handoff Complete message to the mobilitymanagement network element of the CS network; the mobility managementnetwork element of the CS network is adapted to send a Clear Commandmessage to the IWS after receiving the Handoff Complete message sent bythe access network element of the CS network; and the IWS networkelement is adapted to send the Handoff Complete message to the mobilitymanagement network element of the PS network after receiving the ClearCommand message sent by the mobility management network element of theCS network.

(4) If the IWS is integrated with the mobility management networkelement of the CS network, the integrated network element is adapted tosend the Handoff Complete message to the mobility management networkelement of the PS network after receiving the Handoff Complete messagesent by the access network element of the CS network.

The method used by the mobility management network element of the PSnetwork for processing the resources of the UE in the PS network afterreceiving the Handoff Complete message is the same as that used by themobility management network element of the PS network in the previousembodiment, and the details will not be described herein again.

FIG. 12 is a structural view of a mobility management network element ina PS network according to an embodiment of the present invention.Referring to FIG. 12, the mobility management network element includes areceiving unit 121 and a resource processing unit 123. The receivingunit 121 is adapted to receive a Release Request message sent by anaccess network of the PS network or a Handoff Complete message sent by aCS network when a UE is handed over from the PS network to the CSnetwork. The resource processing unit 123 is adapted to processresources of the UE in the PS network after the receiving unit 121receives the Release Request message sent by the access network of thePS network or the Handoff Complete message sent by the CS network.

For a GERAN/UTRAN network, the mobility management network element ofthe PS network may be an SGSN; and for an E-UTRAN, the mobilitymanagement network element of the PS network may be an MME.

The specific procedure for handing over the UE from the PS network tothe CS network is as shown in the method embodiments of FIGS. 7, 8, and9, and the details will not be described herein again.

FIG. 13 is a structural view of a mobility management network element ina PS network according to another embodiment of the present invention.Referring to FIG. 13, the mobility management network element includes areceiving unit 121 and a resource processing unit 123. Based on theembodiment corresponding to FIG. 12, the receiving unit 121 may furtherinclude a first receiving module 1211 and/or a second receiving module1213.

The first receiving module 1211 is adapted to receive the ReleaseRequest message sent by the access network of the PS network when the UEis handed over from the PS network to the CS network. The ReleaseRequest message may contain indication information adapted to indicatethat the Release Request is caused by handing over the UE to the CSnetwork. For example, the Release Request message carries a “Cause” IE,and a value of the IE is set to “Handover Triggered”; or the ReleaseRequest message carries a “Handover Triggered Indicator” IE. Afterreceiving the Release Request message sent by the access network of thePS network, if the first receiving module 1211 finds that the messagecarries the indication information indicating that the Release Requestis caused by handing over the UE to the CS network, the first receivingmodule 1211 may notify the resource processing unit 123 to process theresources of the UE in the PS network.

The second receiving module 1213 is adapted to receive the HandoffComplete message sent by the CS network when the UE is handed over fromthe PS network to the CS network, which specifically includes thefollowing circumstances.

(1) If an IWS network element between the CS network and the PS networkis integrated with an access network element of the CS network, thesecond receiving module 1213 is adapted to receive a Handoff Completemessage sent by the access network element of the CS network.

(2) If the IWS network element between the CS network and the PS networkis integrated with the mobility management network element of the PSnetwork, the second receiving module 1213 is adapted to receive a ClearCommand message sent by a mobility management network element of the CSnetwork.

(3) If the IWS between the CS network and the PS network is anindependent network element, the second receiving module 1213 is adaptedto receive a Handoff Complete message sent by the IWS network element,and the IWS network element sends the Handoff Complete message to thesecond receiving module 1213 after receiving a Clear Command messagesent by the mobility management network element of the CS network.

(4) If the IWS network element between the CS network and the PS networkis integrated with the mobility management network element of the CSnetwork, the second receiving module 1213 is adapted to receive aHandoff Complete message sent by the mobility management network elementof the CS network.

After receiving the Handoff Complete message sent by the CS network, thesecond receiving module 1213 may notify the resource processing unit 123to process the resources of the UE in the PS network.

Furthermore, the resource processing unit 123 may specifically includeat least one of the following modules: (1) a first resource processingmodule 1231, adapted to initiate an implicit user detachment procedureto detach the UE from the PS network; (2) a second resource processingmodule 1233, adapted to reserve all bearers of the UE in the PS networkand indicate an SGW to suspend the bearers; and (3) a third resourceprocessing module 1235, adapted to initiate a delete bearer procedure todelete bearers corresponding to one part of bearer types and reservebearers corresponding to the other bearer types according to differentbearer types, and indicate the SGW to suspend the reserved bearers. Forexample, for GBR bearers, the third resource processing module 1235initiates a delete bearer procedure to delete the bearers; and fornon-GBR bearers, the third resource processing module 1235 reserves thenon-GBR bearers, and indicates the SGW to suspend the non-GBR bearers.

Alternatively, for VoIP bearers, the third resource processing module1235 initiates a delete bearer procedure to delete the bearers; and forbearers other than the VoIP bearers, the third resource processingmodule 1235 reserves the bearers other than the VoIP bearers, andindicates the SGW to suspend the bearers other than the VoIP bearers. Inthis way, original voice bearers of the UE in the PS network may bereleased in time, and other non-voice bearers may be reserved andsuspended. Thus, the UE can continuously provide services to the userafter returning to the PS network.

In the embodiment of the present invention, the resource processing unitmay further include at least one of the following modules, or includevarious combinations of the following modules and the first resourceprocessing module, the second resource processing module, and the thirdresource processing module: (1) a fourth resource processing module,adapted to delete one part of the bearers and reserve bearers accordingto different bearer types, and indicate the SGW to suspend the reservedbearers; (2) a fifth resource processing module, adapted to indicate theSGW to suspend all bearers of the UE, and reserve one part of thebearers and initiate a delete bearer procedure to delete the other partof bearers according to different bearer types; (3) a sixth resourceprocessing module, adapted to indicate the SGW to suspend all bearers ofthe UE, and delete one part of the bearers and reserve the other part ofbearers according to different bearer types; and (4) a seventh resourceprocessing module, adapted to delete one part of the bearers and reservethe other part of bearers according to different bearer types, andindicate the SGW to suspend the reserved bearers and delete theunreserved bearers.

The resource processing unit 123 may also further include at least oneof the following modules: a first bearer suspending module 1237, asecond bearer suspending module 1239, a third bearer suspending module1241, and a fourth bearer suspending module 1243. The second resourceprocessing module 1233, the third resource processing module 1235, orthe fourth resource processing module may send IDs of bearers to besuspended to the first bearer suspending module 1237 or the secondbearer suspending module 1239; alternatively, the second resourceprocessing module 1233, the fifth resource processing module, or thesixth resource processing module sends an ID of the UE to the thirdbearer suspending module 1241 or the fourth bearer suspending module1243 to indicate to suspend all bearers of the UE. The first bearersuspending module 1237 is adapted to receive IDs of the bearers to besuspended and send an Update Bearer Request message to the SGW. TheUpdate Bearer Request message contains the IDs of the bearers to besuspended and states of the bearers, and the states of the bearers areset to “suspend.”

The second bearer suspending module is adapted to receive IDs of thebearers to be suspended and send a Suspend Bearer Request message to theSGW. The Suspend Bearer Request message contains the IDs of the bearersto be suspended, and the Suspend Bearer Request message is adapted toindicate the SGW to set states of the bearers corresponding to the IDsof the bearers to “suspend.”

The third bearer suspending module is adapted to receive the ID of theUE to be suspended and send an Update Bearer Request message to the SGW.The Update Bearer Request message contains the ID of the UE and statesof bearers, the states of the bearers are set to “suspend”, and theUpdate Bearer Request message is adapted to indicate the SGW to setstates of all bearers of the UE to “suspend.”

The fourth bearer suspending module is adapted to receive the ID of theUE to be suspended and send a Suspend Bearer Request message to the SGW.The Suspend Bearer Request message contains the ID of the UE, and theSuspend Bearer Request message is adapted to indicate the SGW to setstates of all bearers of the UE to “suspend.”

The seventh resource processing module may further include at least oneof the following subunits: (1) a first processing subunit, adapted tosend an Update Bearer Request message to the SGW, in which the UpdateBearer Request message contains IDs of bearers to be suspended and IDsof bearers to be deleted as well as states of the bearers, the states ofthe bearers to be suspended are set to “suspend”, and the states of thebearers to be deleted are set to “delete”; (2) a second processingsubunit, adapted to send an Update Bearer Request message to the SGW, inwhich the Update Bearer Request message contains a suspend list of IDsof the bearers to be suspended and a delete list of IDs of the bearersto be deleted; (3) a third processing subunit, adapted to send a SuspendBearer Request message to the SGW, in which the Suspend Bearer Requestmessage contains a suspend list of IDs of the bearers to be suspendedand a delete list of IDs of the bearers to be deleted; and (4) a fourthprocessing subunit, adapted to send a Suspend Bearer Request message tothe SGW, in which the Suspend Bearer Request message carries the ID ofthe UE and a delete list of IDs the bearers to be deleted.

After the SGW suspends the bearers, the SGW subsequently receivesdownlink data packets on the suspended bearers but does not triggerpaging. The SGW may buffer these downlink data packets, and may alsorelease resources used by the suspended bearers between the SGW and adownlink user plane network element, for example, release downlink TEIDsused by the suspended bearers. For example, for an E-UTRAN network, theSGW releases resources between the SGW and an eNodeB; for a UTRANnetwork, the SGW releases resources between the SGW and an RNC or a 3GSGSN; and for a GERAN network, the SGW releases resources between theSGW and a 2G SGSN.

Through the mobility management network element in a PS network providedby the embodiment of the present invention, the receiving unit 121receives a Release Request message sent by the access network of the PSnetwork or a Handoff Complete message sent by the CS network when the UEis handed over from the PS network to the CS network, and the resourceprocessing unit 123 processes the resources of the UE in the PS networkafter the receiving unit 121 receives the Release Request message sentby the access network of the PS network or the Handoff Complete messagesent by the CS network, so that the processing of the resources of theUE in the PS network is achieved when the UE is handed over from the PSnetwork to the CS network.

Through the above description of the embodiments, it is apparent tothose skilled in the art that the present invention may be implementedthrough software on a necessary universal hardware platform, anddefinitely may also be implemented through hardware; however, in manycases, the former is more preferable. Therefore, the technical solutionsof the present invention or the part that contributes to the prior artcan be substantially provided in the form of a software product. Thecomputer software product is stored in a readable storage medium such asa floppy disk, a hard disk, or an optical disk of a computer, andcontains instructions to instruct a computer equipment (for example, apersonal computer, a server, or a network equipment) to perform themethods described in the embodiments of the present invention.

The above description is merely preferred embodiments of the technicalsolutions of the present invention, but is not intended to limit theprotective scope of the present invention. Any modification, equivalentreplacement, and improvement without departing from the principles ofthe present invention shall fall within the scope of the presentinvention.

What is claimed is:
 1. A method for processing resources comprising:receiving, by a mobility management network element of a packet switched(PS) network, one of (a) a Release Request message sent by an accessnetwork of the PS network and (b) a Handoff Complete message sent by acircuit switched (CS) network when a user equipment (UE) is handed overfrom the PS network to the CS network, and processing resources of theUE in the PS network; wherein the receiving, by the mobility managementnetwork element of the PS network, the Handoff Complete message sent bythe CS network specifically comprises at least one of: if aninterworking solution function (IWS) network element between the CSnetwork and the PS network is integrated with an access network elementof the CS network, sending, by the access network element of the CSnetwork, the Handoff Complete message to the mobility management networkelement of the PS network after receiving the Handoff Complete messagesent by the UE; if the IWS network element between the CS network andthe PS network is integrated with the mobility management networkelement of the PS network, sending, by a mobility management networkelement of the CS network, a Clear Command message to the mobilitymanagement network element of the PS network after receiving the HandoffComplete message sent by an access network element of the CS network; ifthe IWS between the CS network and the PS network is an independentnetwork element, sending, by a mobility management network element ofthe CS network, a Clear Command message to the IWS network element afterreceiving the Handoff Complete message sent by an access network elementof the CS network; and sending, by the IWS network element, the HandoffComplete message to the mobility management network element of the PSnetwork; and if the IWS network element between the CS network and thePS network is integrated with a mobility management network element ofthe CS network, sending, by the mobility management network element ofthe CS network, the Handoff Complete message to the mobility managementnetwork element of the PS network after receiving the Handoff Completemessage sent by an access network element of the CS network.
 2. Themethod according to claim 1, wherein before the receiving, by themobility management network element of the PS network, the ReleaseRequest message sent by the access network of the PS network, the methodfurther comprises: sending, by the access network of the PS network, theRelease Request message to the mobility management network element ofthe PS network after receiving a Handoff Direction message sent by themobility management network element of the PS network.
 3. The methodaccording to claim 1, wherein before the receiving, by the mobilitymanagement network element of the PS network, the Release Requestmessage sent by the access network of the PS network, the method furthercomprises: sending, by the access network of the PS network, the ReleaseRequest message to the mobility management network element of the PSnetwork after receiving a Radio Resource Control (RRC) Release Requestmessage sent by the UE, wherein the RRC Release Request message is sentby the UE to the access network of the PS network after the UE receivesa Handoff Direction message.
 4. The method according to claim 3, whereinthe RRC Release Request message sent by the UE and received by theaccess network of the PS network further comprises indicationinformation indicating that the RRC Release Request is caused by handingover the UE to the CS network.
 5. The method according to claim 1,wherein the Release Request message received by the mobility managementnetwork element of the PS network further comprises indicationinformation indicating that the Release Request is caused by handingover the UE to the CS network, and the mobility management networkelement of the PS network processes the resources of the UE in the PSnetwork according to the indication information.
 6. The method accordingto claim 1, wherein the processing, by the mobility management networkelement of the PS network, the resources of the UE in the PS networkcomprises at least one of: initiating, by the mobility managementnetwork element of the PS network, an implicit user detachment procedureto detach the UE from the PS network; reserving, by the mobilitymanagement network element of the PS network, all bearers of the UE inthe PS network, and indicating a serving gateway (SGW) to suspend thebearers; and deleting, by the mobility management network element of thePS network, one part of bearers and suspending the other part of bearersaccording to different bearer types.
 7. The method according to claim 6,wherein the deleting, by the mobility management network element of thePS network, one part of the bearers and suspending the other part ofbearers according to the different bearer types comprises at least oneof: initiating, by the mobility management network element of the PSnetwork, a delete bearer procedure to delete one part of the bearers andreserving the other part of bearers according to the different bearertypes, and indicating the SGW to suspend the reserved bearers;indicating, by the mobility management network element of the PSnetwork, the SGW to suspend all bearers of the UE; and reserving, by themobility management network element of the PS network, one part of thebearers and initiating a delete bearer procedure to delete the otherpart of bearers according to the different bearer types; deleting, bythe mobility management network element of the PS network, one part ofthe bearers and reserving the other part of bearers according to thedifferent bearer types, and indicating the SGW to suspend the reservedbearers; and suspending, by the SOW, the reserved bearers, and deletingthe unreserved bearers; deleting, by the mobility management networkelement of the PS network, one part of the bearers and reserving theother part of bearers according to the different bearer types, andindicating the SGW to suspend all bearers of the UE; and deleting, bythe SGW, one part of the bearers and reserving the other part of bearersaccording to the different bearer types after receiving a Suspend Bearermessage; and deleting, by the mobility management network element of thePS network, one part of the bearers and reserving the other part ofbearers according to the different bearer types, and indicating the SGWto suspend the reserved bearers and delete the unreserved bearers. 8.The method according to claim 7, wherein the indicating, by the mobilitymanagement network element of the PS network, the SGW to suspend thereserved bearers and delete the unreserved bearers comprises at leastone of: sending, by the mobility management network element of the PSnetwork, an Update Bearer Request message to the SGW, wherein the UpdateBearer Request message contains IDs of bearers to be suspended and IDsof bearers to be deleted as well as states of the bearers, the states ofthe bearers to be suspended are set to suspend, and the states of thebearers to be deleted are set to delete; sending, by the mobilitymanagement network element of the PS network, an Update Bearer Requestmessage to the SGW, wherein the Update Bearer Request message contains asuspend list of IDs of bearers to be suspended and a delete list of IDsof bearers to be deleted; sending, by the mobility management networkelement of the PS network, a Suspend Bearer Request message to the SGW,wherein the Suspend Bearer Request message contains a suspend list ofIDs of bearers to be suspended and a delete list of IDs of bearers to bedeleted; and sending, by the mobility management network element of thePS network, a Suspend Bearer Request message to the SGW, wherein theSuspend Bearer Request message carries an ID of the UE and a delete listof IDs of bearers to be deleted.
 9. The method according to claim 6,wherein the indicating, by the mobility management network element ofthe PS network, the SGW to suspend the bearers comprises at least oneof: sending, by the mobility management network element of the PSnetwork, an Update Bearer Request message to the SGW, wherein the UpdateBearer Request message comprises IDs of bearers to be suspended andstates of the bearers, and the states of the bearers are set to suspend;sending, by the mobility management network element of the PS network, aSuspend Bearer Request message to the SGW, wherein the Suspend BearerRequest message comprises IDs of bearers to be suspended; and setting,by the SGW, states of the bearers corresponding to the IDs of thebearers to suspend after receiving the Suspend Bearer Request message;sending, by the mobility management network element of the PS network,an Update Bearer Request message to the SOW, wherein the Update BearerRequest message contains an ID of the UE and states of bearers, and thestates of the bearers are set to suspend; and setting, by the SGW, thestates of all bearers of the UE to suspend; and sending, by the mobilitymanagement network element of the PS network, a Suspend Bearer Requestmessage to the SGW, wherein the Suspend Bearer Request message containsan ID of the UE; and setting, by the SGW, states of all bearers of theUE to suspend after receiving the Suspend Bearer Request message.
 10. Amobility management network element in a packet switched (PS) network,comprising: a receiving unit for receiving a Release Request messagesent by an access network of the PS network or a Handoff Completemessage sent by a circuit switched (CS) network when a user equipment(UE) is handed over from the PS network to the CS network, and aresource processing unit for processing resources of the UE in the PSnetwork after the receiving unit receives the Release Request messagesent by the access network of the PS network or the Handoff Completemessage sent by the CS network wherein the receiving unit comprises atleast one of the following modules: a first receiving module forreceiving the Release Request message sent by the access network of thePS network when the UE is handed over from the PS network to the CSnetwork, wherein the Release Request message comprises indicationinformation indicating that the Release Request is caused by handingover the UE to the CS network; and a second receiving module forreceiving the Handoff Complete message sent by the CS network when theUE is handed over from the PS network to the CS network; wherein: if aninterworking solution function (IWS) network element between the CSnetwork and the PS network is integrated with an access network elementof the CS network, the second receiving module is for receiving theHandoff Complete message sent by the access network element of the CSnetwork; or if the IWS network element between the CS network and the PSnetwork is integrated with the mobility management network element ofthe PS network, the second receiving module is for receiving a ClearCommand message sent by a mobility management network element of the CSnetwork; or if the IWS network element between the CS network and the PSnetwork is an independent network element, the second receiving moduleis for receiving the Handoff Complete message sent by the IWS networkelement, wherein the IWS network element sends the Handoff Completemessage to the second receiving module after receiving a Clear Commandmessage sent by a mobility management network element of the CS network;or if the IWS network element between the CS network and the PS networkis integrated with a mobility management network element of the CSnetwork, the second receiving module is for receiving the HandoffComplete message sent by the mobility management network element of theCS network.
 11. A mobility management network element in a packetswitched (PS) network, comprising: a receiving unit for receiving aRelease Request message sent by an access network of the PS network or aHandoff Complete message sent by a circuit switched (CS) network when auser equipment (UE) is handed over from the PS network to the CSnetwork, and a resource processing unit for processing resources of theUE in the PS network after the receiving unit receives the ReleaseRequest message sent by the access network of the PS network or theHandoff Complete message sent by the CS network; wherein the resourceprocessing unit specifically comprises at least one of the followingmodules: a first resource processing module for initiating an implicituser detachment procedure to detach the UE from the PS network; a secondresource processing module for reserving all bearers of the UE in the PSnetwork and indicate a serving gateway (SGW) to suspend the bearers; athird resource processing module for initiating delete bearerprocedure(s) to delete bearers corresponding to one part of bearer typesand reserve bearers corresponding to the other bearer types according tothe different bearer types, and indicate the SGW to suspend the reservedbearers; a fourth resource processing module for deleting one part ofthe bearers and reserve the other part of bearers according to thedifferent bearer types, and indicate the SGW to suspend the reservedbearers; a fifth resource processing module for indicating the SGW tosuspend all bearers of the UE, reserve one part of the bearers, andinitiate a delete bearer procedure to delete the other part of bearersaccording to the different bearer types; a sixth resource processingmodule for indicating the SGW to suspend all bearers of the UE, deleteone part of the bearers, and reserve the other part of bearers accordingto the different bearer types; and a seventh resource processing modulefor deleting one part of the bearers and reserve the other part ofbearers according to the different bearer types, and indicate the SGW tosuspend the reserved bearers and delete the unreserved bearers.
 12. Themobility management network element according to claim 11, wherein theresource processing unit further comprises at least one of the followingmodules: a first bearer suspending module, a second bearer suspendingmodule, a third bearer suspending module, and a fourth bearer suspendingmodule; the second resource processing module, the third resourceprocessing module or the fourth resource processing module sends IDs ofbearers to be suspended to the first bearer suspending module or thesecond bearer suspending module, or the second resource processingmodule, the fifth resource processing module or the sixth resourceprocessing module sends an ID of the UE to the third bearer suspendingmodule or the fourth bearer suspending module; wherein: the first bearersuspending module is for receiving IDs of bearers to be suspended andsend an Update Bearer Request message to the SGW, wherein the UpdateBearer Request message contains the IDs of the bearers to be suspendedand states of the bearers, and the states of the bearers are set tosuspend; the second bearer suspending module is for receiving the IDs ofthe bearers to be suspended and send a Suspend Bearer Request message tothe SGW, wherein the Suspend Bearer Request message contains the IDs ofthe bearers to be suspended, and the Suspend Bearer Request message isfor indicating the SGW to set the states of the bearers corresponding tothe IDs of the bearers to suspend; the third bearer suspending module isfor receiving the ID of the UE to be suspended and send an Update BearerRequest message to the SGW, wherein the Update Bearer Request messagecontains the ID of the UE and states of bearers, the states of thebearers are set to suspend, and the Update Bearer Request message is forindicating the SGW to set states of all bearers of the UE to suspend;and the fourth bearer suspending module is for receiving the ID of theUE to be suspended and send a Suspend Bearer Request message to the SGW,wherein the Suspend Bearer Request message contains the ID of the UE,and the Suspend Bearer Request message is for indicating the SGW to setthe states of all bearers of the UE to suspend.
 13. The mobilitymanagement network element according to claim 11, wherein the seventhresource processing module comprises at least one of the followingsubunits: a first processing subunit for sending an Update BearerRequest message to the SGW, wherein the Update Bearer Request messagecontains IDs of bearers to be suspended and IDs of bearers to be deletedas well as states of the bearers, the states of the bearers to besuspended are set to suspend, and the states of the bearers to bedeleted are set to delete; a second processing subunit for sending anUpdate Bearer Request message to the SGW, wherein the Update BearerRequest message contains a suspend list of IDs of bearers to besuspended and a delete list of IDs of bearers to be suspended; a thirdprocessing subunit for sending a Suspend Bearer Request message to theSGW, wherein the Suspend Bearer Request message contains a suspend listof IDs of bearers to be suspended and a delete list of IDs of bearers tobe deleted; and a fourth processing subunit for sending a Suspend BearerRequest message to the SGW, wherein the Suspend Bearer Request messagecarries the ID of the UE and a delete list of IDs of bearers to bedeleted.
 14. A method for processing resources during a handover of auser equipment (UE) from a packet switched (PS) network to a circuitswitched (CS) network, the method comprising: sending, by a mobilitymanagement network element in the PS network, a delete bearer requestmessage to a serving gateway (SGW) to delete Guaranteed Bit Rate (GBR)bearers of the UE; and sending, by the mobility management networkelement, a message to the serving gateway to suspend a non-GuaranteedBit Rate (non-GBR) bearer of the UE.
 15. The method according to claim14, wherein the message is a suspend bearer request message.
 16. Themethod according to claim 14, further comprising receiving, by themobility management network element, a release request message from anaccess network of the PS network or a handoff complete message from theCS network.
 17. A mobility management network element comprising: amemory storage comprising instructions; and one or more processors incommunication with the memory storage, wherein during a handover of auser equipment (UE) from a packet switched (PS) network to a circuitswitched (CS) network, the one or more processors execute theinstructions to: send a delete bearer request message to a servinggateway to delete Guaranteed Bit Rate (GBR) bearers of the UE; and senda message to the serving gateway (SGW) to suspend non-Guaranteed BitRate (non-GBR) bearers of the UE.
 18. The mobility management networkelement according to claim 17, wherein the message is a suspend bearerrequest message.
 19. The mobility management network element accordingto claim 17, the memory storage includes instructions to receive arelease request message from an access network of the PS network or ahandoff complete message from the CS network.